Subsequently , a guerrilla liberation war Military_operation was fought Hostile_encounter against the Axis occupying forces Military_operation and their locally established Building puppet regimes , including the fascist Independent State of Croatia and the Government of National Salvation in the German-occupied territory of Serbia , by the Communist-led republican Yugoslav Partisans .

Simultaneously , a multi-side civil war was waged between the Yugoslav communist Partisans , the Serbian royalist Chetniks , the Croatian fascist Ustashe and Home Guard , Serbian Volunteer Corps and State Guard , as well as Slovene Home Guard troops .

Both the Yugoslav Partisans and the Chetnik movement initially resisted Defending the occupation .

The Axis mounted Connect a series of offensives intended to destroy Destroying the Partisans , coming Motion close to doing so in the Battle of Neretva and Battle of Sutjeska in the spring and summer of 1943 .

With support Supporting in logistics and air power from the Western Allies , and Soviet ground troops in the Belgrade Offensive , the Partisans eventually gained Getting control Control of the entire country and of the border regions of Trieste and Carinthia .

Operation Alfa ( ; ) was an offensive Military_operation carried out Military_operation in early October 1942 by Italian , Croatian and Chetnik forces against the communist-led Partisans in the Prozor region ( today in Bosnia and Herzegovina ) , then a part of the Croatian puppet state , the Independent State of Croatia ( NDH ) .

Faced with heavy weaponry and seriously outnumbered , the Partisans retreated Departing and withdrew Departing from Prozor without significant fighting Hostile_encounter .

The Kosovo Operation Military_operation ( October 15–November 22 , 1944 ) was a series of military operations Military_operation leading up to one final push Influence during World War Military_operation II , launched Process_start by the Bulgarian army ( commanded Control by Major General Kiril Stanchev ) with the assistance Assistance of Yugoslav and Albanian Partisans to expel Removing German forces from Kosovo and prevent Preventing_or_letting the retreat Escaping of German forces from Greece .

Partisans and Chetniks captured Conquering towns that weak German garrisons had abandoned .

The largest liberated territory in occupied Europe was created Creating by the Partisans in western Serbia , and was known as the Republic of Užice .

The Chetnik leader Dragoljub Mihailović abandoned GiveUp the uprising in late October and entered Arriving into negotiations with the quisling government and the Germans in order to destroy the rival Partisans .

After the collapse of the uprising , Territory of the Military Commander was largely pacified until the return of the Partisans and the Belgrade Offensive in second half of 1944 .

It was the first of two German-led operations Military_operation targeting Aiming mainly Yugoslav Partisans in eastern Bosnia between 15 January and 4 February 1942 .

The insurgents in the area of operations included Cause_to_be_included some groups of the communist-led Partisans and some of Serb–chauvinist Chetniks .

The failure Earnings_and_losses of the Axis forces to decisively engage the Partisans during these operations necessitated Causation a further major offensive , Operation Trio , in the area immediately south of where Operations Southeast Croatia and Ozren had taken place Process_start .

These included Cause_to_be_included the communist-led Yugoslav Partisans and Serb nationalist Chetniks .

Operation Trio coincided with and contributed Giving to the polarisation of the almost exclusively Serb rebels in eastern Bosnia into two groups : the Serb-chauvinist Chetniks and the multi-ethnic and communist-led Partisans .

The Chetnik movement in eastern Bosnia , at best a confederacy of local warlords , was strengthened Cause_change_of_strength by mass defections Escaping from the Partisans .

The operation was directed Aiming against the Užice Republic , the first of several `` free territories '' liberated by the Yugoslav Partisans .

After the offensive commenced Process_start on 20 September 1941 , the Partisans initially received Receiving assistance from local Chetnik formations in opposing Agree_or_refuse_to_act the Germans , but after weeks of disagreement Quarreling and low-level conflict Hostile_encounter between the two insurgent factions about how the resistance should proceed , the Chetniks launched an attack Attack on the Partisans in the towns of Užice and Požega on November 1 which resulted in the Chetniks being repulsed Defending .

After the offensive commenced Process_start on 20 September 1941 , the Partisans initially received Receiving assistance from local Chetnik formations in opposing Agree_or_refuse_to_act the Germans , but after weeks of disagreement Quarreling and low-level conflict Hostile_encounter between the two insurgent factions about how the resistance should proceed , the Chetniks launched an attack Attack on the Partisans in the towns of Užice and Požega on November 1 which resulted in the Chetniks being repulsed Defending .

The Partisans then counter-attacked Attack decisively , but by early December had been driven Motion from liberated area by the German and Serb collaborationist offensive .

The uprising Change_of_leadership was started Process_start by the local population as a response to persecutions of Serbs by the Ustaše and was led by Chetniks and Yugoslav Partisans .

It later became Becoming an integral part of Yugoslav post-war mythology , which celebrated the courage and martyrdom of outnumbered and outgunned Partisans and civilians .

In the spring of 1942 , Yugoslav Partisans in central and west Bosnia liberated Change_of_leadership Bosanski Petrovac , Drvar , Glamoč and Prijedor .

During the winter , Partisans inflicted Bodily_harm heavy casualties on the Germans .

A great loss for the Partisans was the death Death of their capable and distinguished commander , Mladen Stojanović , known as `` Komandant Mladen '' , who was killed in March 1942 by the Chetniks under Rade Radić .

In Široka Luka about 500 wounded Partisans were killed Killing .

It is estimated Cause_change_of_position_on_a_scale that during the battle , the Partisans lost Death about 1,700 soldiers , while the Axis forces lost Death about 7,000 .

Operation Rösselsprung ( Knight 's move ) was a combined Cause_to_amalgamate airborne and ground assault Attack by the German XV Mountain Corps and their allies on the Supreme Headquarters of the Yugoslav Partisans located in the Bosnian town of Drvar in the Independent State of Croatia during World War II .